The present invention relates to a developing apparatus for CRT panels, and more particularly, to a developing apparatus for CRT panels that has a process in which evaporated organic matter, inside a developing gun, so as to be condensed, coats powder and it is sprayed out of the developing gun.
In the prior art, the process for forming a phosphor face on CRT panels includes the applying of a black matrix which entails the steps of washing panel, application polymeric conductor and photoconductor layer, charging, exposure, black matrix developer, and fuser. Next, the process for forming a phosphor face includes the following steps for applying a phosphor material: P.C. charging, G exposure, G developer, fuser, P.C. charger , B exposure, B developer, fuser, R exposure, R developer, fuser. In this way, phosphor material comes to be applied through a method of electrophotographically manufacturing a screen assembly.
In the above process of forming a black matrix and each of the R, G, B phosphor materials through a method of electrophotographically manufacturing a screen assembly, the developing apparatus of the prior art includes: a body; a panel fixing portion placed on the upper part of the body; a developing gun in which a charger electrode is placed; a powder supply line which supplies black matrix and powder of each R, G, B phosphor material (hereinafter referred to as just powder); a powder supply apparatus, connected to the powder supply line; an air supply line that supplies air to the developing gun and is installed separately from the powder supply line; an air supply apparatus connected to the air supply line; and an electric supply apparatus which supplies electricity to the charger electrode inside the developing gun. The structure of the above panel fixing portion is formed so that it grounds the panel it secures.
In the above formation of the prior art developing apparatus, when the CRT panel, which is positively charged and is exposed, is fixed to the panel fixing portion, the powder supply apparatus and the air supply apparatus start operating, and through the powder supply line and the air supply line, powder and air is supplied to the developing gun and the electricity supply apparatus provides electricity to the electrodes of the developing gun.
The powder, which by following the flow of the air that is supplied to the developing gun gets sprayed out from the developing gun. While being forced out, the powder is electrically charged (to the same positive pole as the panel) by the corona discharge of the electrode fixed to the exit of the developing gun.
The panel fixed to the panel fixing portion has formed, an electrical line through the charged and un-charged portion. This is realized because the charged portion and the un-charged portion are formed in a determined pattern by the operations of charging and exposure, and because the conduction layer is grounded by the panel fixing portion. As a result, the powder, which is charged to the same pole as the panel and shot out of the developing gun, follows the electrical line and adheres to the un-charged portion and is developed in a determined pattern.
When using the prior art developing apparatus composed as in the above, because the process of coating the powder, supplied to the developing apparatus, with a material used to control electrical charge and a material used for securing, needs to have the supplementary process of using heat or acetone to fix the developed powder to the panel, the developing process becomes complex.
Also, in the process of using heat or acetone to fix the developed powder to the panel, if the conduction layer or the photocunductive layer is thin, they become damaged by the heat or acetone. If this happens, when developing the three R, G, B colors, developing is barely achieved.